Updating CMake requirement to 2.8.12 RC 1

[Alexander Neundorf]

Hi,

On Tuesday 20 August 2013, Stephen Kelly wrote:
> Hello,
> 
> CMake 2.8.12 RC 1 was released a few hours ago:
> 
>  http://thread.gmane.org/gmane.comp.programming.tools.cmake.user/47443
> 
> Updating to that will allow us to get on the home straight with regard to
> our buildsystem files.

please wait with updating the required version until 2.8.12 final is out.
There have been complaints about requiring unreleased versions of cmake, e.g. 
by Aaron.
I actually don't have to say that, since it should be obvious to everybody 
here, I also object to requiring non-final versions of cmake, it just makes 
life harder for everybody trying to contribute.
Except the very very early phase before cmake 2.4.3 or so, we never did that, 
and I don't think we need to start with that now.

Alex